You are able to collect real-time metrics based on cumulative metrics.

You can choose the number of snapshots to display and the time to wait between snapshots.

You can choose to filter on name and objectname based on predicates (see the help).

You can work on all the cells or a subset thanks to the CELL or the GROUPFILE parameter.

You can decide the way to compute the metrics with no aggregation, aggregation on cell, objectname or both.

To get the exadata_metrics.pl script: Click on the link, and then on the view source button and then copy/paste the source code. You can also download the script from this repository to avoid copy/paste (click on the link).